Australian scientists said Wednesday that they have uncovered a "very rare" 2,000-year-old natural sea pearl while excavating a remote coastal Aboriginal site. The pearl is the first found on the continent.

Australia's University of Wollongong on June 3, 2015: a "very rare" 2,000-year-old natural pearl (the first found on the vast island continent) uncovered while excavating a remote coastal Aboriginal site

Kat Szabo, an associate professor at the University of Wollongong said that archaeologists came across the pearl while excavating the site on the north Kimberley coast of Western Australia.

"Natural pearls are very rare in nature and we certainly -- despite many, many (oyster) shell middens being found in Australia -- we've never found a natural pearl before," Szabo, who specialises in studying shells at archaeological sites, told AFP.

The discovery's location is particularily significant because "the Kimberley coast of Australia is synonymous with pearling, and has been for the better part of the last century, " says Szabo

The pink-and-gold-coloured pearl is almost completely spherical, and measures five-millimeters in diameter. Because the pearl was nearly perfect round researchers were able to use a micro CT scan to test its age as well as prove that is was naturally occurring rather than a modern cultured pearl.

Pearl producing oysters have been used in rainmaking ceremonies in indigenous cultures, and their shells have been found in the central desert more than 930 miles away. Archaeologists have known about the rainmaking rituals but were not aware of how far back in history they had been practiced until now.

"Studying the pearl has led us to the study of the layer in which it's found," Szabo said.

"In indigenous terms, that's telling a really interesting story about a cultural tradition to do with pearl shells which we knew historically but we've never been able to prove that it went back into the past."

The pearl is set to go on display at the Western Australian Maritime Museum in Perth later this month, with details of the find published in the Australian Archaeology journal.